SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7f9fe0f406421f798b826e7006317acba33e9f344a9a6fc468dedcc4cdbd7c19' 
  AND token = 'gk48ibb3DtpxfcEhYCZ11mMa0n6skMqp3hhWeP1pXwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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