SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0517e2020e57ad9a69023d7ff939b0e2905bd6f405cd11c515ca890ffcc842e1' 
  AND token = 'iMzIavBm5MSUAH2asKhZ11uWyVf4j9pqGDFfucwon3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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