SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0dbac0c44507a0a625c399984b875df218736bf739424ec48fd4b2a25df1fbc' 
  AND token = 'Lo7vSKBQ4D9CfAQQiU0VKylunRSpQdiNq96KBLcmMDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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