SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d434ea858a00c875f9d49019805391ab12c7d153a672f6f55cbec539ac2b267' 
  AND token = 'OnZvzj1vPlQQ7QSIKrsOldC8aBlHnMtdWV/KfLrvO9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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