SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f8f60b3dc5bebf16a10bb59324ea5956f4fa925d750ae6d19feee1706f471bb' 
  AND token = '6rLyeRDurJmOLDFDCsSQU1qsgXLHUOvPTzlmzY1Y1xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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