SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df31329995de5044ac77b08817dcece68e0b2c9d4ab086903d1ab226167d28df' 
  AND token = 'ksLqSagEWrylUhUsAca8cj/Ng4qpsjZnif3QZLc8Aj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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