SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8931fdb99d2d2f8b26315147a12bb00d768277dfa3e074ad30ea763cf0ec268' 
  AND token = 'ImIRL4YLjA8cXHoRnJhqvwd/Bq1nQ2cVmfIfi3z9PGQ=' 
  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"
    }
  }
}