SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '146b325a1edf63a973851704e8887e039002b1f41cbeaa53148ef1f1f079f49a' 
  AND token = '7G7/nIbycIfnBFmzScjnGzzpg8Cs8QLU6035OmBZJ9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}