SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '098fa821882d087438f5eb4cdceebf9878413adfd886a52c2b650186badff226' 
  AND token = 'exrBXp0EL8Z4fYX5tk8bYhFomMASKnvy1tqtjRMNwf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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