SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c771ab52e8fd66a460dc406994340299b846590d34d309d6736856539914fd2b' 
  AND token = 'yiNpq9pWozuaWee3vSrhI2Q/KZbv6j21qVzaUhL1/Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}