SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '202f4b71aa652fee390288b9dead34e4b04252706bbccaeb5b91d0f02ab99150' 
  AND token = 'Rzj+ntmfmPMbLXGg63PIqprtyASpBz5mk9ndjA9nT1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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