SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6b86d4c0acbd5c6dae94d85ea23fc6104232cade8119cef84796ace1d5a2765' 
  AND token = '2WN0rR6pAxsQey1Z8Br5kFhjTFNPIMc43BiSfxPFYes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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