SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0bc4ba4a336e6df2f4903588d468b04f488b7516f068cc83dacea906e29b8413' 
  AND token = 'WTBGVesKWf23EPuwPdXGzmN914PYZjseiqY9HVq1zwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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