SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f162846ef6c27299b67a5a7fb44ae60cae580e9e979c019551b6422f68d12b3f' 
  AND token = 'W5KQ0RVFnkomfqXDLVlfeGW/VdfIiE87oPZk9EveIIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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