SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ab2d0ad37fd2d5228cc3995fcf1b5d007fde6688b4b7ec637b9f847649cbcec' 
  AND token = 'fVlbU6VsElchtq0uAVQgaoixMIneEszH/wQXl1LqugQ=' 
  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"
    }
  }
}