SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c89cca301c677a18c3de84343adcf799b4aa11b04a858f90f07c1976f817d99' 
  AND token = 'eow8QRr7bzlR1pbTKSMtgerGBkx8bEuMWzsHsPqLVfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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