SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8565be005dfc05b8189077b1ac7bcb6c2e83f07a2c724e76da8c02e7bd54e94' 
  AND token = 'e0L5kJcYmtHMeZNXdhvHiS96SQN2PKJlwgDXY64DGq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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