SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dba0aac703876cfdfd59ef3eda4071d5da4c25c00b7cbb8031e8b619d0e90e40' 
  AND token = 'qm4ObmXwwbOSZBe6CnVQ5UZAgWwQojckiOHMNVZ+v2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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