SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cf350a966783d7cd83bd5379f82052f37137e6b5b083e1688bf9c0f7fbc4451' 
  AND token = 'XhBrf7laXo6J69z7D2riLPGNBlRw61XQqzmJ+agbPpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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