SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f965b276a5f9dc97c62fed3250ce0fae2b7916959d0663b1c5fd7a3fc05681a9' 
  AND token = '4yNHCySpaZpiCEPfu1gpR59yu8ZSmnTwbjX5qx92JJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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