SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b2084533363243a352034506131dea1b2e4afa40db2530a4735bb0a6ff089da' 
  AND token = 'qNGDd3FzLqBFajGAgyy3ZgnxAAiKDslIhkWqHhbl/VQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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