SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64bf819db3c0c062c8d2b737bfb01e4f66266ca9690f5894e60d431aa96df940' 
  AND token = 'umOnJTHqSaiqo9JNjqtz16PBCmq+Q5l9Rd4zI8KXVLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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