SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f757c60b0693527b7ac4933b8c24333069429317587f3528d907db1a8f5fe1d9' 
  AND token = '4+5qmvYFiuXOgUFzjjsiJh7XMrrWZW7RcXf2w6Lca0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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