SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c89daa3e946ddb9df170ba1c71b5146605adf424c75492ffbc54532f74700d58' 
  AND token = 'fWaySOGAH+mRO4q/vY/0LSvXeZZId60u8QCenJtZWNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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