SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37b6e9216ee8acd745858bf10a73fb94bade62fdcefa89233cbc4d5bfbe8fb08' 
  AND token = 'JiAl0g0Pfaa4yAPf5TbpSW9iDvxGKkl+mSV4iPM6vDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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