SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31f9dd8bdd1902cabf43784a6b1534ec955409fe27411383ccc8c0b2ba031086' 
  AND token = 'szYhIQOdxGL6QZ34/Bd2CslIPK1/MYQAh35EOhmCOGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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