SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1653357cd9ad7beaf231d621bce6b47653a0ad576512882baab1cebade4a588' 
  AND token = 'mhQJpT0vdnCsA2neX6ByFgoAym04wbuIi9q11VwYEn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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