SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e6d7dd1aaf15913e241cbe1c87581da6897db62ac5ab6abb947aeba44c2c7d4' 
  AND token = 'FeuHbVKZR4eaTJaKHpUsOpVBl+b5b/jSa4qsdXVE1Gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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