SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a015c74e3c9c111d944feaef6f38345f9590b6e6fa74be823fbc5ce7aac37b9b' 
  AND token = 'QWjXVuuL8untE4lgaMNLvxkVL6S+GEJzOJbaM3X3wM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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