SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ff372fc17fb874ca1fb8234f642ceb8aa9f54168b1735d4d743e81b824c049c' 
  AND token = 'LkD9JGyHtBXcN7nB3MKDvAkaLA1ORhaVq6qDP3pZMcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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