SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb5d50ca7b4146f8979cce64eb150c439bf9c2547133860fd0c2a8d151f0f429' 
  AND token = 'SWcgKflZq1uPZS6ngoH99YsqenavcGBiFRczDZiAmQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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