SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d34fd30537019ec5488903b9897e050a83fd52c8af24d99f8cb29a0d4e38926' 
  AND token = 'SwD6q1NlER7BHlfCT2Qvn4kzZJy+7BTzquPVliYAXIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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