SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7359aac8a21ac16cb1266eb4f1879c49ede07d44c25d69ae0d0f9a4a10046c8a' 
  AND token = 'zisKhqy8UMbXPD0pUEEGDfyRiC/Yaexti0prmlyQmZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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