SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d71f5a639c7efabbc8aac609394e2fdbfa7c5df2147a9828296fec2eb308538' 
  AND token = 'ozaP9n463xEAfKMeAzEP0Yz7l2TbwtBmdp+wcg2a480=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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