SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b86ad44221232e96618e099ace6ec2b88287b125b9a57530aaeb866d4a56ec1' 
  AND token = 'QdPd0Xn0rHApBeg9SE6N6zofqte+jApjJe8sGjdTGBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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