SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18f889ddbaf613c313e2cf0ad222ff951fa0d586d6bb59402e72c2ec6c335843' 
  AND token = '4latHHb8zKHVfV7C7uQdy+X39OJFlLYmR44bKT0/Glw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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