SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89a93e57ceec75431f9b4cc3b5ce359b1c03f274a84a5116b6e92067c0a70147' 
  AND token = '2ycHuaEm5f7MzflOzOapaGY/GhXid5SouMZRQoMiSFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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