SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c75d10b9186f3af45a4f665af1592466a8c1a87e54be1dbdc72074c3b940815' 
  AND token = 'eGeBBqr4+YDO+1vWCOvlurjY+FcV5padojTFPpJbLks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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