SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a75ea32f142640908e9b44450a34429ff2952d021a53c61e0fed61e543f85d35' 
  AND token = 'tyA7EQ1vxCpO8RUwyzYw5xYI3Q34kRXIGwQ1QVaQwWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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