SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '30df90c67d88e3d61ff99b6f91dd30f5c47c8af3ebe9af964e283a173606fcc1' 
  AND token = 'S+0Q2jfiL08RZ78m+4Uffk1XZ1FEpdMO5fXz830C5a0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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