SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1567317a28f7bb3212bc125a7c7230603f99c2d65bd524c6cb0b6655f98d52f0' 
  AND token = 'PJC3L+GonljJWFTSIXOIXacYxedXHEAF1lh/jV/1LmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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