SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c2f0eb70dda73aff2fa955bb58c880e34f76b9f565120a24d155cc343fdce5f' 
  AND token = 'uL1EiBog4gRI9uAkxzfwEBis53z0ohfkTHIbyJgzrPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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