SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7a21b1759e6d7d05f23b568bd603a5dfd42f4b4127206ba910cc96b30318ba4' 
  AND token = 'zg/NmPnsKz6SCm5bYNzwXhdR5pa4APsqIIV5CPuGxa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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