SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c5a1eb5e0869969ff524063cd9f2adc285946643bf91aa9e290ce7a278de9eb' 
  AND token = 'a7S9fG1S2fRPnGr6lqBzm8jO3+nCDlNqRp7hOsqZTU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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