SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db10ece15e1639c333ce284af4bcb4887cba64709943d252d916f52aafa4ac69' 
  AND token = 'DKioJzdS9eVN1ywPSNg7isWkLY/Qa1gleYCr9uYfFBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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