SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d9a0f6c54826df501e94e23ab98792df1699d5112efc5b4eff5bfbad108230' 
  AND token = 'OiyFLVyw3sMflU5WXhghsD4GPJgLJCWXfn2lT4zZuxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00092

JSON explain

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