SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e604fcf0dfb1bda608b0e3d61804f082a948ca77be75ecef91b32947377e8ea6' 
  AND token = '43dJ2ziMMKn0JOLm2OyVs7Y4GEqXdn5NvRYIqt9sF0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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