SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee1855880607d29974cdc974e3b010c5520cc583b7d34887b0d1b422ecfc0a1b' 
  AND token = 'Kd0gnWrAW5zq/ZkKDx9B8OKcZOjMJ149UBlA3dn+F8c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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