SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '245fe027a157a8fb8166f8097e15c590a196539f77cdb1990578d147f14d4915' 
  AND token = 'XMve6s7Hmvhh+Pn+1e6tCZ8uoS+s/LbKWGDszgCk+Bs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}