SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9067d669d429a99758550ea940e06a764be74ff516720251efce50ac9628c3a8' 
  AND token = 'HFd25xpg6Vu+3O8OvS4MKbZo//NfZMCc1HnwOdUwzKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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