SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c4404e93dd17fe536a577c19651224a9b0e52b487e131bf2e2d63c5fec35f4e' 
  AND token = 'hZyukmzjBVucTNdLGKYBpxxUGAOg8CfFQlqQoGogJ4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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