SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4537e73a4a249df9e4f717cd026fce7f41b25642fbd3e7ff469692c79045860' 
  AND token = 'wshiqkQrBGdLXzcfFZU1DcrCC2lOd9Nu3PA4b6TXdrA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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