SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e2381b3f5b34810731ca06fdb729a7718816d702aa830981f156dff5ab945bc' 
  AND token = '6MGze6rDLNE8tCbcO9eIIVS1+itMdV6EjtoOqDIx7vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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