SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d24d53c27d2e032c8f5cfd5aac38d6093060ef389be91537488df606d0fe12a' 
  AND token = 'nf0+REk+FXcfYdPpbFiNprCnVYKO1lERZrAQZnazsXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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