SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c591d64d4b6aa63c899af2222b74867f6f372c16aefc7fba99bcdd314eab65a' 
  AND token = 'm9I74np82VM5MHMi4cZLe1wihlzSL8TtUAJO1Dnezkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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