SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8d292d7cc7f8c5065ea69e0865f6fe20315134e23986f3987d997882491568da' 
  AND token = 'gd8dngNMYP1+Amf+2tFjOzpkr4wggGKL1V9k/AJ/JZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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