Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ec21f2a008f1f4177b4b323673d8c1a9cfcfada7dfc1ccb2815e5d5623ebec6' 
  AND token = 'uP/8Cfo1kdm11PpHh4IG7v/sXPMuSmEklNLs8kDGG2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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