SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8885375f3473afcb38cbdbae08b9db80a0706aff12f4e1c9b0d5231b79e5ddb' 
  AND token = 'O1/PB/VhnV+n4d+QLv9u3jjWCgM9GbxdnL2QzhlxKqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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