SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fbaa17b805dd225fae3c6fd37624d69f09bf9685ae92aa08854c85d6a731e75' 
  AND token = 'h2hsVRIzJ8lmp+0kuNVvWwMKdx8tKrdJwUleBLmUwNE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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