SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9435911f7d3a31374ea1189dd0bbc6e1dd9943da223832019d756cbe0041412' 
  AND token = 'GniFCjEvGs9ir0YoVPfTIykwe4NfoJnbdD1D9VlbfFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}