SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70bd50a5156345fe016841d58bbbbb14e8785a694a18a83508bbf19e3a59665e' 
  AND token = 'qD7aPIc8V/EKUEljwLpUZFSt6guH0/ITS+zXWf8ZPn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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