SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29c396a3b5905f8961718d68565f04cc3bfbb735552589538092b0f48b336f0d' 
  AND token = 'epsijv0tDDQJzOu3pnOo3aPR9pBdO3aOt2dF1oy5Lds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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