SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a0fd71aaaa3081db96f9c95e4eb859812428aaf12a5c15672cbb5971cf33af4' 
  AND token = 'WxqVL4UnrYFUgCR53+/B6mYEe/mh64J2AtZaH/+AaBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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