SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98d69ccf1cd5ac70ae918b040aa1e174a384c8b1532828115017ac884a39b2e5' 
  AND token = 'lqRB4jJhkqrToEuGkChfux+QT8JrcEqNy5UNrAXuSkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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