SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce3e2f4094b54c9f4acfc9cae1f079eaba303b99b06b59d78bd44dee64cd2c5c' 
  AND token = 'Tt2eeeYSsYqx8Xss+EkKcif1sMkKX+92hyZP7Zuq104=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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