SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8c561a0b9d2101c8fa640982d71f84cbc0758bd2ae4a0951214efcc515eab3ed' 
  AND token = 'ZsJSWQxnlLomwww+Stk3cJAZSuZbpLxVS7o9mvdeKpA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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