SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5839b51c25597277464564e38fdd5d738a128cebd28823a720f474c1c12cdcd9' 
  AND token = 'CLohVf1EEhFxJHAFGEoeqZbFQrgK7AutE1hv3q5k/xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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