SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2f20ab738165fb2c6ae62ee5d86eeccac7d289079d29266996118a433cf27b2' 
  AND token = 'tcilPPKRnJlpxRgHKvrYl3k+VtlC9fXSCoqY9uHizEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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