SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9a9db3a887afe0f275d87fd3c5fa2eaef23b4dac3c642521e543760e0b1adc5' 
  AND token = 'rN6tRymWtKSF0CdmuZ/xXhEihDoChtN0OG3n9dru7PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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