SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '158573ba58a5dcdbe9b5f83fb0fd31b53fd504c284f9613bf09acdc55db1081f' 
  AND token = 'KLKa8NyeHXraXLxhMx5CsIIn8gSGcI17z7wD60a1LnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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