SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07f3bbed6109e2a9c679470c5f30957988c45e8dce133bb05d42da38de62a927' 
  AND token = '4365CoSnDYxee4p5uaeXb4P5G4ZkS/71fkRqPjvf97A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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