SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60c04e526d9ffc7c7a0696565cacdfec7455ad53c28be9a9e95262f2179fe1e3' 
  AND token = '6jXTBKwjam/LCXnDOR1wstWMHQqdLy8QZFuDgdnn6xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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