SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59a4e884c94b59d5e521ce15b6765e1afddfad5fda0a362257b6804130c8ae19' 
  AND token = '9cHxPpCwzrDpRQbkuK/j7GEWxleJa+GwoiE0xypZcaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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