SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb9c59091dd09638082e1428de41623643d3be225eddbf8e8c8a3decfd3cb5d8' 
  AND token = 'gwvIK3Am5M93Vpvi7LkekxK5rvF9cVPrRiEymNbsNcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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