SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dc9a62a8439e669b984103968b35874964435265707da8c0982b5287cfd1797' 
  AND token = 'Gpiu1GKRGFSZowJGuH4Z+yl9D4SWRj7BYgO7pdl1LCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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