SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edd27f856351d32784e9b8a817699a56d45a39eb991e7b40510004d830176408' 
  AND token = 'FnpqoDwXbDvKko4BtUKnetgcIjEaZLlbV52Kr/vmFj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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