SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '821cc51227c3ddc4038487eb94fb41c2bc420b58938a4bde53c8fd0114e48d0d' 
  AND token = 'sH25BcNz9bcwLQ4GPT9xw1muXzJhN9gzX8g0xE+H2xE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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