SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da0eaa28292974476f161461be7367ad808a98cb81a08ce1b8e8de06fcac4ce9' 
  AND token = 'P18y8UG3J8onNhfptxxxnwpTvONjUoaT/vywM/vwN2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}