SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee755f50a67221e5aa351ab985fa897ef7012296a237aade6d581985dcc1fb57' 
  AND token = 'TBNi6gNaN8gxR68KExjpdubyMwoRjftJR47OkKcZv/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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