SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d276c1e9ecb3fd56b53094b12a3065eb46a25d486fde88305c3165abba26c68' 
  AND token = 'TDpV+J0BBhI4GQb8vUfwgFlIieTqSIxoY1w4rfgKYic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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