SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56e34623f7d0953721c30b8ef29a2005f074ec164c4fcbe756bf889a9c1fc0c8' 
  AND token = 'I79VMHy/23/ezOnllXeNPq0LUFaiwCTSRNuZQVcEEEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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