SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cadda61b25ccef31ef128fb65487b8e19dfab2c1fe9f088082c9d6e72d23defc' 
  AND token = 'rPQESjeolnRuMr0EKDnSV9Ydo81VsFIKtYDNatWlLDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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