SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4507d0c9145615e400656fd00ef134859f52d61523777d996c7fca27a9cc4374' 
  AND token = 'SKpnTKprQvrhSKgkLrh1NiiglbzUcDVnPoVb0cz9xa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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