SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f08ff3df7e60c8353cf20cfff7d32ec2310997649e8eb32f78b41845c1e61260' 
  AND token = 'ZtQJsW2VywtlSfy5BZgCIUzyVPBi26YrfVrNQ4U9GRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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