SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95396935a201e3d0848df9616183da52ee8cb2d3c0af1f0edb71ee4a108a51d4' 
  AND token = 'dRCTpNXm4+qC41nXE33+AiKjaaEI3rSGgqSPHT2EvCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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