SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e93617791d55a5700b95260cce96a546aba8e4ec5a94974852c3caace0755615' 
  AND token = 'Cn9kNxg2hY7hEt/ALlhfF1sPLTsxVKWY0Tq3tBEwCkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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