SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fca49ed94fad1fa9b84ac04f84eed0ea29bd1b3b93e3cea97c7cb0df014db71' 
  AND token = 'nVgG0Lx3+qGoBGYLue+eOB0xjW+FuhpNKEq3p8RyDvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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