SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b58af4b661d7c097e6a9aacbaaafd9335dc967e443324a2c6c4a0653112a1743' 
  AND token = 'unFtBi0vEo1NuDBiyO9Mqvc4MpuCP0B2f+ptu8IvQiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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