SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0bb5593ec23e9197ae6e376ac3be04320c6f9174b54ee6bbf13781681c4261c' 
  AND token = 'QWLlpLORkWkFwtJ3T0sY58ZL5mi1W5v7zRx7Y/pPCtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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