SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '99869d7dcd75ef4ab0f67ae40c69a46a8cc22ba718fb57790e438fcf7b6e44f6' 
  AND token = 'yajEy4Hp1Sgn80dhcWfehlKdsZaSWL8VXCKp1zRYrFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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