SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '047a50655220ecd571fa10009b245be0e98f65858e5dc5506d892bfbcf96c895' 
  AND token = 'xUNqXm9naX/auTZVbH+80X1spscWTEhslNP1xhuxEIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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